Packaging heavy, bulky machinery such as lawn and garden tractors, lawn mowers, snowmobiles, boat motors, engines, air compressors, air conditioners and the like, presents many unique considerations. Because such machinery is by its nature difficult to handle and store, conventional double-wall or triple-wall laminated corrugated paperboard containers have long been recognized as being unsuitable for packaging heavy equipment. As a result, cleat-reinforced containers with mating rigid base and top frames have been developed. Generally, the cleats, the base frames, and the top frames are made of wood. These shipping containers are also often referred to as wood-cleated boxes.
The conventional wood-cleated box consists of a wood-reinforced corrugated paperboard body, a wooden top frame, and a wooden base frame. Generally, the interior walls of the corrugated paperboard body are provided with wood reinforcement cleats that are vertically aligned in order to provide stacking strength for the container. The corrugated paperboard body gives the container definition and maintains the position of the wood reinforcement cleats. The base frame often referred to as a skid or pallet, supports the container and the product packed therein. The top frame closes off the container and provides a surface upon which another container may be stacked. The top frame, the vertical reinforcement cleats in the body, and the base frame cooperatively provide the container with top load strength, such that the containers may be shipped and stored in multi-unit stacks.
Conventional packaging of heavy equipment in typical wood-cleated boxes call for the product to be packed by first being fastened to the base frame. The corrugated paperboard body is then placed over the product and over the base frame. The corrugated paperboard body is stapled to the base frame in a conventional manner by a compressed-air driven staple gun. The top frame is inserted into the upper portion of the corrugated paperboard body and supported by the reinforcement cleats on the corrugated paperboard body. The top flaps of the box are then folded and glued or stapled closed. Steel or plastic banding may then be provided to gird the completed package.
While these conventional wood-cleated containers have proven adequately effective for packaging heavy equipment, several problems existed. As described in U.S. Pat. No. Reissue. 34,557, handling of such wood-cleated boxes with clamp trucks led to separation of the base frame from the corrugated paperboard body. Because the packaged product is often extremely heavy, a tremendous downward force is exerted against the base frame with respect to the corrugated paperboard body. The staples that secure the base frame to the corrugated paperboard body often worked through the paperboard and were pulled loose. As a result, the base frame and the packaged product secured thereto fell from the corrugated paperboard body, causing irreparable damage to the container, significant damage to the product, and potential harm to bystanders. U.S. Pat. No. Reissue. 34,557 addressed the problem of the base and body separation to assure container integrity during packing, shipping, and storage. Attaching strips on a lowermost portion of the corrugated body aligned with the base frame. The corrugated paperboard body was then secured to the base frame by driving staples through the body and the attaching strips into members of the base frame. This provided a rigid contact connection between the base frame and the corrugated paperboard body, which reduced the potential for component separation.
While this improvement has resolved this problem, such cleated-containers experience other unresolved problems. During shipment, twisting, lateral forces are exerted on the cleat-reinforced corrugated paperboard containers. When three or four containers are stacked one on top of the other in a truck, rail car, or the like, the jostling action resulting from typical transport often causes the top flaps on the upper container to prematurely loosen and open. Often this is caused by a twist or torquing motion on the cleat-frame of the container. Such a torque or twist causes the top frame to push through the top flaps, thus opening the container and exposing the product inside to possible contamination or damage.
Another problem is the price of corrugated paperboard. The top flaps often represent 10% to 30% of the cost of the corrugated paperboard in the body. While the top flaps provide a closed covering for preventing dust, dirt, or other contamination from contacting the product in the container, other wrapping mechanisms may suitably protect the product at a lower cost. For instance, the product may be enclosed in a plastic sheet or bag. The top flap is no longer needed to function as a protective covering, and thus reflects a cost with reduced benefit.
Further, the top flaps hide the members comprising the top frame. The top flaps thus appear to provide a support surface for other containers. If a container of the same size is placed on the top frame, the loading is distributed from the top frame directly through the reinforcement cleats to the base frame. However, if a smaller but heavier container is placed on the top flaps, such as in less-than-full truckload shipments, the smaller, heavier container may tear the top flaps and fall through into the container, thereby damaging both the falling container and the product held in the cleated container.
It is thus seen that a need exists for an improved cleat-reinforced corrugated paperboard shipping container which protects articles within the container while increasing the integrity of the container. It is to the provision of such that the present invention is primarily directed.